I need tips on formation and tactic for the next season

[SindreI]

But Who should I change out, and what positions should the new player have?

[Steppenwolf]

But Who should I change out, and what positions should the new player have?

Can't say whom to sell tho, don't know how your players were performing in this season... You will need at least one side midfielder or winger for each side, so you could play almost any formation... looking at the stars, you strongest starting eleven is in 5-3-2 formation, but if any of them is playing bad, then give them some chance in the next season... and if they continue to play bad, then sell them...